1. Field of the Invention
The present invention relates to an apparatus for changing the size of a photographing aperture in a camera, for example, from a standard size to a panoramic size, or a half size and vice versa, and it also relates to an apparatus for protecting light intercepting plates incorporated therein
2. Description of Related Art
There are known cameras in which the size of a photographing aperture can be varied. To change the photographing aperture size, it is known to provide rotatable light intercepting plates which are rotated about an axis to vary the photographing aperture size. This known mechanism for changing the photographing aperture size, however, requires a large space in which the light intercepting plates are rotatably accommodated, which prevents construction of a compact and small camera.
It is also known to provide an adaptor type of light intercepting plate which is detachably attached to an aperture frame that defines an aperture. It is, however, troublesome to attach and detach the adaptor to and .from the aperture frame. The adaptor cannot be inserted or removed once the film is loaded into the camera, therefor the size of the photographing aperture cannot be changed. Furthermore, it is necessary for a photographer to inconveniently carry the adaptor which may easily be lost.
In conventional cameras having a photographing aperture whose size is variable, the size of the photographing aperture can be changed when a back cover of the camera is opened. The photographing aperture size thus changed is retained regardless of the open or closed state of the back cover. The light intercepting plates, which are provided in the vicinity of the aperture frame; are retractably moved or exposed into the aperture to partly cover the aperture to thereby change the photographing aperture size from a standard size (full size) to a size other than the standard size, for example, a panoramic size. Consequently, when the back cover is open, there is a possibility that the light intercepting plates are damaged or broken by an accidental touch of a photographer's finger, etc., therewith. One solution to prevent the light intercepting plates from being damaged or broken is to reinforce the light intercepting plates themselves or a drive mechanism thereof. This solution, however, leads to a big and heavy photographing aperture size varying apparatus which requires a larger accommodation space, thus resulting in a big and heavy camera.